[vlc-commits] upnp: Fix potential race during tear down.

[Hugo Beauzée-Luyssen]

vlc/vlc-3.0 | branch: master | Hugo Beauzée-Luyssen <hugo at beauzee.fr> | Thu Aug  8 11:53:20 2019 +0200| [cfe426a6803404edcf0fe99cfefe8a327c17a6a1] | committer: Hugo Beauzée-Luyssen

upnp: Fix potential race during tear down.

If two threads call UpnpFinish at the same time (or more precisely, if a
2nd thread calls UpnpFinish before the first one sets UpnpSdkInit to 0)
we can end up double releasing most libupnp resources
(cherry picked from commit 2873288c7c7b1f62f67ce41b1928b326019f7898)

> http://git.videolan.org/gitweb.cgi/vlc/vlc-3.0.git/?a=commit;h=cfe426a6803404edcf0fe99cfefe8a327c17a6a1
---

 modules/services_discovery/upnp.cpp | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/modules/services_discovery/upnp.cpp b/modules/services_discovery/upnp.cpp
index f1037c82c8..e3a6496b3e 100644
--- a/modules/services_discovery/upnp.cpp
+++ b/modules/services_discovery/upnp.cpp
@@ -1698,7 +1698,7 @@ UpnpInstanceWrapper *UpnpInstanceWrapper::get(vlc_object_t *p_obj, services_disc
 void UpnpInstanceWrapper::release(bool isSd)
 {
     UpnpInstanceWrapper *p_delete = NULL;
-    vlc_mutex_lock( &s_lock );
+    vlc_mutex_locker lock( &s_lock );
     if ( isSd )
     {
         delete UpnpInstanceWrapper::p_server_list;
@@ -1709,7 +1709,6 @@ void UpnpInstanceWrapper::release(bool isSd)
         p_delete = s_instance;
         s_instance = NULL;
     }
-    vlc_mutex_unlock( &s_lock );
     delete p_delete;
 }